Analysis of biological or environmental specimens typically requires sample-derived molecules to be present in solution. However, many types of samples (animal and plant tissues, soil samples, etc.) have a relatively tough structure whereby molecules of interest are contained within cells and the extracellular matrix and thus are not available for dissolution. Examples of samples that are difficult to extract are plant seeds, whole insects, and fibrous tissues. Preparation of such samples for analysis typically involves mechanical disruption of a specimen structure by a grinding, homogenization, or maceration operation in a suitable reagent.
While most analytical methods of separation and detection of specimen molecules are highly automated, initial sample preparation steps frequently require operator involvement and manual manipulations. Generally, large specimens and suspensions of single-cell organisms, such as mammalian or plant cell cultures, bacteria, or fungi, are processed in large-scale batch-mode or continuous high flow homogenizers, or systems that use high energy ultrasound, also known as ultrasonic cavitation. Small tissue samples of small amounts of cell suspensions cannot be efficiently processed in such equipment. As the sensitivity of analytical methods increases and discovery research or clinical diagnostics applications demand increasingly small amounts of biological material (such as small tissue biopsies) to be analyzed, new methods of preparing such samples for analysis are required. However, specialized equipment for processing of small samples is not free of limitations, such as lower homogenization efficiency, sample loss or operator exposure to potentially hazardous samples.